what are the side effect from botox in the neck, back, and the front of the shoulder?

I went for my botox injections shots like i do every three months, (which i never had a problem till now). the day after i dot the shots i can't lift my middle finger up or can't make the number 2 with my pointed finger or the middle finger. the pointed finer is fine it goes up but the middle fingure doesn't. and i can't stick the middle finger up by itself. so i went to the hospital tonight (saturday) told them that i had a car accident two months ago, which finally i went to my family doctor cause i was have pain in my right elbow. which the doctor popped it back in. and i didn't have any problems with my finger.  then i told the hospital doctor i had botox shots on thursday. so she took an x-ray of my had to make sure nothing was broking and there wasn't. which is good.  i guess. but she said with the botox there's a chance that i might not be able to move my middle finger again cause the botox messed up my nerve. so is there a chance that the botox caused this that i can't move my middle finger?